<!DOCTYPE html>
<html style="height:100%">
<head lang="en">
  <meta charset="UTF-8">
  <title></title>
</head>
<body style="height:100%">
<canvas id="canvas" style="height:100%"></canvas>
<script>
  window.onload=function(){
//    获取canvas标签
    var canvas=document.getElementById('canvas');
    if(canvas.getContext('2d')){
      //    绘图上下文环境
      var context=canvas.getContext('2d');
    }else{
//      解决浏览器不支持canvas的问题
      alert('当前浏览器不支持canvas，请更换浏览器后再试');
    }
  }
</script>
<!--二维的点阵模型-->
<script src="js/digit.js"></script>
<!--程序的主逻辑-->
<script src="js/countdown.js"></script>
</body>
</html>